Topics include, Machine Tools & Tooling, Precision Measuring, Materials and their Properties, Electrical discussions related to machine tools, setups, fixtures and jigs and other general discussion related to amateur machining.
pete wrote:If I recall correctly you don't have a mill Dianne
I do have a mill but was thinking of using the drill press because it has much better 'feel'.
My guess is it's a model part with holes that size correct? If that's right then the pump isn't real large.
Yes, it is a Von Broklin duplex pump in 3/4 scale.
Do you have a lathe milling attachment?
Nope, but my drill press is an older floor model of good quality with a good chuck. Drilling in a milling attachment on the lathe would help clear chips better but I don't have a milling attachment.
Quite accurate edge finding and drill tip to part location can be done to under 1/2 a thou with little more than a bucks worth of Zig-Zag cigarrette rolling papers.
I am planning to use a surface plate and my height gauge to lay out the hole locations. As for depth, 5 to 10 thou should be sufficient accuracy.
I've drilled a fair number of #56 (.046") tap drill holes for 0-80 threads with a floor standing drill press and my BP clone and there both about the same for actual feel while drilling. Pretty much none And have also done some in stainless. Depends on what type of mill you have or if it's got a movable spindle or the whole head has to be moved and what you have for collets to go with it I suppose. With small ER type collets and these small drills you can choke up on the drill and only leave as much drill below the collet as you need. That really helps to stiffen things up. Takes a long time as well since you need to peck drill every couple of drill diameters deep. Good brand name and sharp drills do make a massive difference of course. It's still a non comfort job for me since all you can think of while doing it is snapping the drill off below the surface. Do you have any access to back issues of the HSM magazine Dianne? Sometime in the mid to late 1980s they published a pretty good artical for a minature add on sub table for use with very small drills on drill presses or mills that lifted the work into the drill and gave the required feel. It would be exactly what your needing and only used a couple of bucks in 1/2" thick aluminum plate and a small wood router type ball bearing to build it. I tried Googleing images for it and didn't come up with anything on it so far.
I can control depth in several ways, depending on which machine I use it on.
Quite successful at NOT breaking small twist drills, and getting my projects done.
~RN
The sensitive drill adapter is certainly an option. If you have a choice of machines use it on the machine with the least runout. Small drills are really sensitive to runout. I have one of the sensitive drill adapters but never needed it because I acquired a sensitive drill made by High Speed Hammer Co. It goes up to 5800 rpm so it is far better suited to small drills than my mill at 3000 rpm.
johnfreese wrote:...I acquired a sensitive drill made by High Speed Hammer Co. It goes up to 5800 rpm so it is far better suited to small drills than my mill at 3000 rpm.
You are the only person other than my dad that I know that has one of those.
My Cameron is nice, and it can go up to 30,000 RPM and down to a 0.002 drill, but the High Speed Hammer will kick it's butt in torque.
And have also done some in stainless. Depends on what type of mill you have or if it's got a movable spindle or the whole head has to be moved and what you have for collets to go with it I suppose. With small ER type collets and these small drills you can choke up on the drill and only leave as much drill below the collet as you need. That really helps to stiffen things up. Takes a long time as well since you need to peck drill every couple of drill diameters deep. Good brand name and sharp drills do make a massive difference of course. It's still a non comfort job for me since all you can think of while doing it is snapping the drill off below the surface. Do you have any access to back issues of the HSM magazine Dianne? Sometime in the mid to late 1980s they published a pretty good artical for a minature add on sub table for use with very small drills on drill presses or mills that lifted the work into the drill and gave the required feel. It would be exactly what your needing and only used a couple of bucks in 1/2" thick aluminum plate and a small wood router type ball bearing to build it. I tried Googleing images for it and didn't come up with anything on it so far.